KNIJN Crypter
I made this app in response to several alarming events such as the push to outlaw encryption and several services that got exposed for having lousy end to end encryption.
By using this app I don't have to put my faith in other implementations of encryption as I can use my encryption anywhere I want it to be used whether the service is usually encrypted or not (eg: Gmail).
As long as you can transmit text through said service, you can actually use this app for encryption.
This app protects people from prying eyes of governments & ISP's, whoever manages the service you use and even to a certain extend people who look over your shoulder.
The first two are protected by using E2EE, the company who manages the service cannot crack the encryption because it is completely managed outside of their reach and people who look over your shoulder only have a small amount of time to actually see the decrypted text in a pop-up before it disappears at which point only the encrypted text is visible on the screen until the user decides to decrypt it again.
https://github.com/BRUHItsABunny/KNIJN-Crypter
This has been an ongoing project of which it's first iteration was made in 2014, until now they always came with a PHP back-end but that wasn't end-to-end encrypted.